A Vancouver man entered guilty pleas Tuesday in federal court in Portland to conspiring with at least two others to participate in a sophisticated international designer drug ring that generated millions of dollars.

Ryan Ahidjou "Bo" Scott, 33, is expected to face eight years in prison and has been ordered to forfeit more than $5.36 million to the federal government, a portion of the proceeds of his criminal drug sales, according to court testimony and documents.

Scott conspired with three others to import raw and unregulated chemicals from Peru and China to manufacture and distribute designer drugs marketed under brand names such as "K2,'' "Orisha'' and "Vesuvius.''

To try to evade law enforcement detection, Scott and other members of the conspiracy marketed the products as "incense'' or "summoning powder,'' and placed disclaimers on packaging that said, "Not for Human Consumption.'' But the products were sold to be ingested or inhaled to achieve a "psychoactive or stimulant high," similar or greater than street drugs such as cocaine, marijuana, speed and ecstasy, prosecutors said.

The federal investigation was part of the government's escalating crackdown on the designer drug trade. According to the U.S. Department of Justice, manufacturers have created synthetic drugs by coating plant materials with chemicals that mimic THS, the active ingredient in marijuana.

They're often marketed as herbal incense, bath salts, jewelry cleaner or plant food, but have caused significant abuse, addiction, overdoses, emergency room visits, organ damage and overdose deaths, according to justice officials. They've become increasingly popular with teens and young adults, but haven't been approved by the Food and Drug Administration for human consumption or for medical use, and are often more potent and dangerous than marijuana.

On Tuesday, Scott pleaded guilty to one count of conspiracy to distribute controlled substances and one count of conspiracy to commit money laundering. He conspired to transfer over $3 million in domestic drug sales through international wire transfers involving Canada, the United Kingdom and the Cook Islands, Assistant U.S. Attorney Leah K. Bolstad wrote in court papers.

Federal agents searched Scott's warehouse in May 2012 and discovered a "large-scale synthetic drug manufacturing operation,'' with hundreds of pounds of dried plant material, kilograms of uncut chemical cannabinoids in powder form and other products that were confirmed as comparable to controlled substances.

Prosecutors alleged that after Scott's arrest and while he was out of custody under pre-trial supervision, he continued to illegally import, market and sell new synthetic controlled substance analogues while using false identities and email accounts and conspired to sell and obtain fraudulent Canadian passports. He made another $240,000 while convincing the federal court that he was eligible for a court-appointed public defender, prosecutors said.

"In other words, the tax dollars of hard-working Americans went to fund court-appointed co-counsel for a man who, while under pre-trial supervision, had a quarter of a million dollars deposited into his bank accounts thanks to his continued importation and distribution of illegal designer drugs that are harmful to the community,'' Bolstad wrote in court documents. "This is an embarrassment for our federal pretrial system.''

Scott faced another federal indictment in 2013 for new drug conspiracy and passport fraud charges, but those charges will be dismissed under the plea agreement reached in the 2012 case.

Scott remains in custody. Among the lawyers now representing him is high-profile Portland criminal defense lawyer Janet Hoffman.

Sentencing is set for Sept. 22 at 9:30 a.m. before U.S. District Court Judge Ancer L. Haggerty.